Many of recent image capturing apparatuses such as a digital camera are capable of not only still image shooting but also shooting and recording of a video with sound. Shooting in various modes can be performed by one digital camera. In recent times, there also exist an image capturing apparatus capable of shooting a still image while shooting a video with sound and an image capturing apparatus capable of recording a scene that has previously been unattainable by composing a plurality of continuously captured images.
An image capturing apparatus disclosed in Japanese Patent Laid-Open No. 2005-57378 thins out a series of image data obtained by driving an image sensor in a progressive scanning mode into the video recording pixel count, and processes and records the image data as a video. If the user instructs to shoot a still image during video shooting, the image data is processed and recorded as a still image without being thinned out. According to this technique, it is possible to shoot a high-quality still image during video shooting without interrupting video shooting and also shoot the video without lowering the frame rate.
Japanese Patent Publication No. 7-97841 discloses an image capturing apparatus capable of obtaining a video having a wide dynamic range by composing a plurality of images captured under different exposure amounts by periodically changing the exposure time. According to this technique, the images are continuously captured while alternately changing the exposure time to long and short durations and composed, thereby generating a high dynamic range video (to be referred to as an “HDR video” hereinafter).
Conventionally, however, no detailed processing method has been examined for a case where a still image shooting instruction is input to record an HDR still image during HDR video recording. The timing of still image shooting instruction input is asynchronous to continuous image capturing processing for video recording. For this reason, as for which frame is to be used to generate an HDR video or HDR still image, a wide range of variations can be considered in accordance with required performance.